Abstract
Species with broad geographic ranges may experience varied environmental conditions throughout their range leading to local adaptation. Variation among populations reflects potential adaptability or plasticity, with implications for populations impacted by disease, climate change, and other anthropogenic influences. However, behavior may counteract divergent selection among populations. We studied intraspecific variation in hibernation physiology of Myotis lucifugus (little brown myotis) and Corynorhinus townsendii (Townsend's big-eared bat), two species of bats with large geographic ranges. We studied M. lucifugus at three hibernacula which spanned a latitudinal gradient of 1500km, and C. townsendii from 6 hibernacula spread across 1200km latitude and 1200km longitude. We found no difference in torpid metabolic rate among populations of either species, nor was there a difference in the effect of ambient temperature among sites. Evaporative water loss was similar among populations of both species, with the exception of one C. townsendii pairwise site difference and one M. lucifugus site that differed from the others. We suggest the general lack of geographic variation is a consequence of behavioral microhabitat selection. As volant animals, bats can travel relatively long distances in search of preferred microclimates for hibernation. Despite dramatic macroclimate differences among populations, hibernating bats are able to find preferred microclimate conditions within their range, resulting in similar selection pressures among populations spread across wide geographic ranges.
Highlights
Studies seeking to understand broad scale ecological and evolutionary processes often consider variation in phenotypic traits among geographically isolated populations (Garland Jr and Adolph 1991; Kawecki and Ebert 2004)
Torpid metabolic rate was related to temperature but the effect of temperature did not vary among sites
Torpid metabolic rates measured in winter were slightly greater (0.1 ± 0.07 mW g-1) than when measured during swarming, but given that no similar effect was observed for EWL and no seasonal effects were observed for M. lucifugus, this may be a spurious result
Summary
Studies seeking to understand broad scale ecological and evolutionary processes often consider variation in phenotypic traits among geographically isolated populations (Garland Jr and Adolph 1991; Kawecki and Ebert 2004). Organisms with broad geographic ranges may have to contend with dramatic differences in climate and environmental conditions throughout their range and, exhibit different strategies to cope with this climatic and environmental variability. Some species may adopt a generalist strategy, but specialist-generalist tradeoffs suggest there may be selection for alternate strategies (Kawecki and Ebert 2004). Populations of widespread species may adapt to local conditions that may be relatively consistent among years, but vary dramatically across the species range
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
